x int Horizontal coordinate of the pixel to be set; i.e. the number of the pixels from the left edge of the DIB to the desired pixel.

y int Vertical coordinate of the pixel to be set; i.e. the number of the pixels from the bottom edge to the desired pixel. (0 in this function points to the bottom row of pixels, rather than the top row.)

lpPixelIndexUnion LPPIXELINDEXUNION Pointer to a PIXELINDEXUNION - structure defining the binary pixel value for the pixel.